A taller man might have more strength to draw the bow than a significantly shorter man, provided the latter is not especially muscular. Well, I can’t see how height would affect power of crossbow. Also, I don’t think taller man can reload the crossbow slightly faster, because reloading crossbow involves movement of entire body, so a minor difference in strength might not be an issue. In addition, you need to bend to reload the crossbow, I think it is easier for short people to reload the crossbow, they should have slightly better posture and balance.
Ahem, back to the topic. Yes I think the trait should only affect melee weapons.
